I have a Jeep Cherokee with the 4.0L. It has an M62 right now. I want to build the entire engine up and put some giant blower on it to make around 800hp. I think I need like an M122 or higher or a twin-screw 2.0L or higher, but how do I actually calculate that to see if it will work on paper? I am *guessing* that as I leave 2.0L and move more towards 4.0L my power capability increases, but I am not sure it's that simple.

I'd build an intercooling system. Maybe 2 stage with laminova cores. Just an idea.

I'm just trying to get a better fundamental idea on what I'd need from the supercharger so I can broaden my search and find something more cost-effective.

I can definitely do this with a turbo, and I know it can be done with a supercharger, but I've never personally seen it. Also, I have to take into consideration what I'd need to do to adapt it to the inline 6 cylinder.

Any input is appreciated.

 

At what RPM? if 800 is WHP, what drivetrain losses? What kind of pressure losses do you have from airbox to intake? At 800 crank HP my guess is you need to move ~1160 CFM of air

 

Man, these are awesome questions. Seriously, thank you for the reply. This is exactly the type of response I was hoping for.

How do you determine (or calculate) drive-train losses? What about pressure losses? Are there tools to do this besides installing a bunch of the same sensor? I'm sure there has to be some kind of tool I don't know about. I tried joining a mechanical engineering group on Facebook, but there was too much weird spam and I had to leave it. I'm not even sure how you measure CFM, but I do know what it is. These are all great questions. I am going to have to look them up. I just wanted to reply and say thank you and maybe hope you reply again with something I can use to aid my research.

What do you mean by "airbox to intake"? What part of the system are you calling "intake"? I've basically redone everything until the throttle-body which is on the back of a superchager. It's a M62 though and I am changing that. That is why I'm asking these questions. The airbox was removed and the 3" pipe is now a 4" pipe that runs into the cowl and in there is a giant filter that makes my cowl-cover look pregnant. However, I am going to design and create a totally new cowl-cover that has something like an airbox built into it with some kind of scoop or induction vent right above the filter. The entrance will allow for much more air this way. I'm also considering making pipe from carbon fiber, because then I can make a kind of "weird" design that allows for larger oval-shaped pipe.

How would I determine if there was a bottleneck at the air entrance? The only way I can think of is to run it on a dyno how it is, then remove everything and run it open to see how much increase there is. How would I determine the maximum beneficial size for intake piping? Because if I could determine that then it would dictate the filter-size and I could built everything around that function. That is how I'd prefer to do it, but I'm not sure about how to do the testing.

Just FYI this is just a project that I'm doing purely for fun and to learn. I'm not involved in professional motorsports or anything. I just want to make a Jeep straight-six that is incredibly powerful like Newcomer Racings turbo-build, but with a supercharger instead because superchargers are way more badass, haha. Mad Max didn't drive a turbo car.

 

By intake I do mean intake manifold.

Take a look at https://www.autospeed.com/a_111109/hdg34ultp_1/cms/article to see some good suggestions on measuring pressure drops on the intake circuit. Start with a baseline before adding mods so you can figure out where to focus your effort. If you are like me and will need to do it on your own, having a camera to record the gauge as you call the rpm and speed would be helpful.

You seem to have the skills and access to the tooling required to machine ducting in metal and carbonfibre, so you can aim on having no more than a 2psi pressure drop from before the airfilter to the intake manifold while others (like me ) have to make do with parts cobbled together. In fact, I moved to a new state and do not know a good aluminum welder I can ask to chop open an intake manifold and weld a flat plate for me.


I too have been interested in Laminovas, but from what I remember it is not just a matter of filling an intake manifold with them. I remember reading in their website that you need to craft air passages to keep the airflow close to the fins for it to be effective. And that of course means you need to redesign the plenum to provide the chamber volume you seek, capacitor effect and time to interact with intercooler accounted for of course. For my own design I will resort to a junkyard intake manifold which already has a (old-school bar-and-plate) intercooler in it. Right now I am trying to find a place that can hotbath it (and another intercooler I have) and then I will jerry rig some kind of flowbench to have an idea of pressure drop in its stock configuration (before I find a place to weld it as mentioned above).

One thing I assume you have addressed is straightening your engine; I may be wrong but I do not think your Jeep engine is 2jz-strong tough.

IMHO if you have access to a bench dyno, use it. But you have to know its limitations and then go to car dyno once vehicle is put back together to validate. You probably can use it to design your intake circuit for pressure loss and electronics, but remember it will not help you much for temperature (I would argue even normal dyno testing is dishonest because it is done with hood open instead of closed and enough fans to emulate desired vehicle speed).